Simulations of inertial liquid-lens coalescence with the pseudopotential lattice Boltzmann method

The coalescence of liquid lenses is relevant in various applications, including inkjet printing and fog harvesting. However, the dynamics of liquid-lens coalescence have been relatively underexplored, particularly in the case of liquid lenses with larger contact angles. The coalescence of low-viscosity liquid lenses is numerically investigated by means of the pseudopotential multi-component lattice Boltzmann method over a wide range of contact angles. In two-dimensional simulations, numerical results on the growth of the bridge height are in quantitative agreement with experimental measurements for small contact angles. In addition, a comparison of the simulation results with a theoretical approach based on the thin-sheet equations for liquid lenses shows that these equations accurately capture the bridge-growth dynamics up to moderate contact angles. For the three-dimensional case, the growth of the bridge radius is independent of the equilibrium contact angle of the liquid lenses at the initial stage of growth. The dependency between the growth of the bridge height and the bridge radius exhibits a non-linear to linear transition. Document Type: Original article Cited as: Xie, Q., Harting, J. Simulations of inertial liquid-lens coalescence with the pseudopotential lattice Boltzmann method. Capillarity, 2026, 18(2): 41-49. https://doi.org/10.46690/capi.2026.02.01